1. Technical Field
This invention relates generally to knife blades, and more specifically to a brace for holding a curved blade for cutting windshields out from their frames in vehicles. The invention is a brace for a windshield knife blade which distributes the forces for operating the blade from the repairman's hand and wrist down the arm to the forearm and elbow.
2. Related Art
Often it is necessary to remove the windshield from its frame in a vehicle in order to repair or replace the windshield. The current practice when installing a windshield is to bond it around its circumference to its frame with a polymer adhesive, for example, a polyurethane adhesive. Therefore, whenever it is necessary to remove this windshield it is necessary to cut through the adhesive in order to free the windshield from its frame.
In the windshield repair industry there is provided a standard manual knife for,, cutting through the windshield adhesive. One version of this knife is depicted in FIG. 1. This knife has a generally cylindrical handle which holds a generally planar, pointed blade with a nearly 90.degree. bend in it, the bend being generally perpendicular to the width of the blade and generally perpendicular to the centerline of the handle. The thickness of the blade varies from the front to back, it being thicker in the front away from the repairman for stiffness and strength, and thinner in the back towards the repairman to allow for a sharpened, thin cutting edge there. The blade may have a short cable with a handle pivotally connected to a wider portion of the blade to assist the repairman in pulling the blade through the tough adhesive. The blade is used by pushing its pointed end through the adhesive, and then pulling it with both hands towards the repairman to cut through the adhesive.
However, during use, this prior art knife tends to twist and rotate in the repairman's hand, causing an erratic cut and discomfort for the repairman. After prolonged use, the effect of this twist and rotation is to cause fatigue and even damage to the repairman's hands, wrist and forearm.
Therefore, there is a need to eliminate the rotation and twist in the handle of the current manual knife for removing windshields. Also, there is a need to provide a more controlled cut, and to provide more force to the cutting blade making the cut, in the current manual knife for removing windshields.